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authorDave Jiang <dave.jiang@intel.com>2018-12-04 21:31:33 +0300
committerDan Williams <dan.j.williams@intel.com>2018-12-14 04:54:13 +0300
commit9db67581b91d9e9e05c35570ac3f93872e6c84ca (patch)
treeff45815c6b756313755cf3f688cddbecf2cd2fc8
parent76ef5e17252789da79db78341851922af0c16181 (diff)
downloadlinux-9db67581b91d9e9e05c35570ac3f93872e6c84ca.tar.xz
keys-encrypted: add nvdimm key format type to encrypted keys
Adding nvdimm key format type to encrypted keys in order to limit the size of the key to 32bytes. Signed-off-by: Dave Jiang <dave.jiang@intel.com> Acked-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
-rw-r--r--Documentation/security/keys/trusted-encrypted.rst6
-rw-r--r--security/keys/encrypted-keys/encrypted.c29
2 files changed, 25 insertions, 10 deletions
diff --git a/Documentation/security/keys/trusted-encrypted.rst b/Documentation/security/keys/trusted-encrypted.rst
index 3bb24e09a332..e8a1c35cd277 100644
--- a/Documentation/security/keys/trusted-encrypted.rst
+++ b/Documentation/security/keys/trusted-encrypted.rst
@@ -76,7 +76,7 @@ Usage::
Where::
- format:= 'default | ecryptfs'
+ format:= 'default | ecryptfs | enc32'
key-type:= 'trusted' | 'user'
@@ -173,3 +173,7 @@ are anticipated. In particular the new format 'ecryptfs' has been defined in
in order to use encrypted keys to mount an eCryptfs filesystem. More details
about the usage can be found in the file
``Documentation/security/keys/ecryptfs.rst``.
+
+Another new format 'enc32' has been defined in order to support encrypted keys
+with payload size of 32 bytes. This will initially be used for nvdimm security
+but may expand to other usages that require 32 bytes payload.
diff --git a/security/keys/encrypted-keys/encrypted.c b/security/keys/encrypted-keys/encrypted.c
index d92cbf9687c3..fe0aefd06f83 100644
--- a/security/keys/encrypted-keys/encrypted.c
+++ b/security/keys/encrypted-keys/encrypted.c
@@ -45,6 +45,7 @@ static const char hmac_alg[] = "hmac(sha256)";
static const char blkcipher_alg[] = "cbc(aes)";
static const char key_format_default[] = "default";
static const char key_format_ecryptfs[] = "ecryptfs";
+static const char key_format_enc32[] = "enc32";
static unsigned int ivsize;
static int blksize;
@@ -54,6 +55,7 @@ static int blksize;
#define HASH_SIZE SHA256_DIGEST_SIZE
#define MAX_DATA_SIZE 4096
#define MIN_DATA_SIZE 20
+#define KEY_ENC32_PAYLOAD_LEN 32
static struct crypto_shash *hash_tfm;
@@ -62,12 +64,13 @@ enum {
};
enum {
- Opt_error = -1, Opt_default, Opt_ecryptfs
+ Opt_error = -1, Opt_default, Opt_ecryptfs, Opt_enc32
};
static const match_table_t key_format_tokens = {
{Opt_default, "default"},
{Opt_ecryptfs, "ecryptfs"},
+ {Opt_enc32, "enc32"},
{Opt_error, NULL}
};
@@ -195,6 +198,7 @@ static int datablob_parse(char *datablob, const char **format,
key_format = match_token(p, key_format_tokens, args);
switch (key_format) {
case Opt_ecryptfs:
+ case Opt_enc32:
case Opt_default:
*format = p;
*master_desc = strsep(&datablob, " \t");
@@ -625,15 +629,22 @@ static struct encrypted_key_payload *encrypted_key_alloc(struct key *key,
format_len = (!format) ? strlen(key_format_default) : strlen(format);
decrypted_datalen = dlen;
payload_datalen = decrypted_datalen;
- if (format && !strcmp(format, key_format_ecryptfs)) {
- if (dlen != ECRYPTFS_MAX_KEY_BYTES) {
- pr_err("encrypted_key: keylen for the ecryptfs format "
- "must be equal to %d bytes\n",
- ECRYPTFS_MAX_KEY_BYTES);
- return ERR_PTR(-EINVAL);
+ if (format) {
+ if (!strcmp(format, key_format_ecryptfs)) {
+ if (dlen != ECRYPTFS_MAX_KEY_BYTES) {
+ pr_err("encrypted_key: keylen for the ecryptfs format must be equal to %d bytes\n",
+ ECRYPTFS_MAX_KEY_BYTES);
+ return ERR_PTR(-EINVAL);
+ }
+ decrypted_datalen = ECRYPTFS_MAX_KEY_BYTES;
+ payload_datalen = sizeof(struct ecryptfs_auth_tok);
+ } else if (!strcmp(format, key_format_enc32)) {
+ if (decrypted_datalen != KEY_ENC32_PAYLOAD_LEN) {
+ pr_err("encrypted_key: enc32 key payload incorrect length: %d\n",
+ decrypted_datalen);
+ return ERR_PTR(-EINVAL);
+ }
}
- decrypted_datalen = ECRYPTFS_MAX_KEY_BYTES;
- payload_datalen = sizeof(struct ecryptfs_auth_tok);
}
encrypted_datalen = roundup(decrypted_datalen, blksize);